Do you have to read the Wheel of Time books to understand the series?

In short: no. Much like the shows based off George R.R. Martin’s A Song of Ice and Fire, or what’s clearly the biggest influence here, J.R.R. Tolkien’s The Lord of the Rings, viewers of the series who are familiar with the source material will find enjoyment (or at least a feeling of insider-y knowledge) watching the story come to life. But you don’t have to read all 14 books to follow The Wheel of Time; sure, you might miss out on Easter eggs or the more detailed meaning behind some of the lore, and some of the references will sail past you. But the show very carefully makes sure its settings, characters, and important plot points are easy for newcomers to follow. Also, if you’d read the books, you’d already know from the get-go that Rand was the Dragon Reborn. Spoiler alert!
If you want to know a smidge more about The Wheel of Time’s world without committing to all the books, Prime Video released a series of animated shorts, Wheel of Time: Origins, as part of its “X-Ray” feature, offering further glimpses into the story’s history and mythology.